Once you have a kernel that beats the present offerings, and you have
updated the appropriate index file(s), nothing could be easier.
If you are starting from a fresh install without Level 1 arch defaults,
you need do nothing further: the install process will find your kernel.

Things are almost as simple if you have already installed, and need to
force a redo. First, get rid of old search results by issuing
rm ATLAS/tune/blas/level1/<arch>/res/<pre><blas>_SUMM.
Then, go to ATLAS/src/blas/level1/<arch>, and type :